(CNN) -- Self-help guru James Ray was arrested Wednesday after a grand jury indictment charging him with three counts of manslaughter in the deaths of three participants at an Arizona sweat lodge ceremony he organized last year.

Yavapai County Sheriff Steve Waugh said Ray was arrested at his attorney's office in Prescott, Arizona, Wednesday afternoon.

He will eventually be housed at the Camp Verde Detention Center, the sheriff's office said, and his bond has been set at $5 million.

Ray is charged with the deaths of Kirby Brown, James Shore and Liz Neuman.

Ray's attorney, Luis Li, said that the charges were unjust and that Ray would be exonerated in court.

"This was a terrible accident -- but it was an accident, not a criminal act," Li said. "James Ray cooperated at every step of the way, providing information and witnesses to the authorities showing that no one could have foreseen this accident."

As many as 65 visitors, ranging in age from 30 to 60, attended Ray's "Spiritual Warrior" program at the Angel Valley Retreat Center near Sedona in October.

They spent as long as two hours inside a dome-like structure called a sweat lodge, which was covered with tarps and blankets and had hot rocks and water inside to create steam.

Three people died after spending time in the sweat lodge October 8 and nearly 20 others were sickened. Brown and Shore were pronounced dead shortly after they arrived at a local hospital, and Neuman died October 17 after being hospitalized since the incident.